Proto rail slants

[Anonymous]

I don't know what you call it.
But when you look at a proto steep curve the outside of the track is slightly higher than the inside. Should you try to model this?

[Anonymous]

That's called superelevation, or in layman's terms, banking. It can be successfully modelled for a great effect, but it has to be extremely subtle as to not disrupt the passage of trains. On models, it is mostly just for effect, because our little trains just don't have the mass to require it. At my club, the curve out of the yard has thin electrical wire placed under the outside rail to slightly superelevate it; it makes the trains look better, but I haven't noticed any appreciable operating improvement. I think that if you have large curves that trains will go over relatively fast, then it's worth putting in. There was an article in MR on this subject a few years ago.

[Anonymous]

It's called "superelevation" and, as with highway construction, is used to permit higher speeds on curves.

Superelevation is only needed on model curves for sake of appearance. Particularly in the larger scales, trains look impressive as they bank around curves. However, superelevation can create lots of headaches (read "derailments") if it isn't done very, very carefully.

We superelevated the curves on my club's large HO scale layout. We wish we hadn't, and we are relaying all of the mainline curves (minimum radius 42'), beginning with those most prone to causing derailments.

Raising and lowering the elevation of the outside rail at the entrance to and exit from a curve needs to be done gradually and evenly--and this isn't as easy as it seems in theory. What may appear to be an insignificant dip can can lead to grief in operation.

Also, we used "pre-superelevated" flex track for the main portion of our mainline curves. Unfortunately, most of it too wide in gauge, and wheels with narrow treads have fallen between the rails.

--John

[jfugate]

I add a stripwood shim on the outside rail when laying curves to get the superelevation because it makes the trains look more real, like this:



Stripwood works well because near where the curve meets the straight track you can sand a nice transition in so the outer rail raises gently as the track heads into the curve.

[Anonymous]

I looked into superelevation and found layers of thin masking tape will do the job well and once its ballasted its unnoticeable.

[Fergmiester]

I have superelevated curves on my 22" to 26" 3 to 5% grades.

Am I bragging? No I'm frustrated! Super elevation is really nice but you have to ensure your curves are even and well supported. I lay the cork down then sand the inside down. Strips of wood work just as well.

I also use a thin metal yard stick to insure there are no dips in the track and that transitions are gradual both on the horizontal and vertical planes.

[BR60103]

To properly get into superelevation, you should also gradually get into your curves using easements. Going directly into a 24" radius curve, you should have an immediate jump of 1/16" to 1/8" (for the speeds our models travel at).
There is an interesting prototype term called "cant deficiency" which is how much less than ideal the superelevation can be and not have the passengers complain. i.e. how much can the coffee tilt in the cup.
If you have the roadbed mounted independently of the scenery, you can get superelevation by tilting the supports, but I suspect that this creates other problems as you work round the curves.

[Anonymous]

I'm laying a lot of track right now and I need all the help I can get with superelevation.
Should I do it or no?
is it too much hassle?
And what is stripwood? I've never heard that before.


Thanks

[Anonymous]

Seems we dropped this thread, so I thought I'd bring it back up with a question regarding the article in the July MR about "Perfect" tracklaying.

In the article the author states he uses styrene blocks in varying incements on every 15th tie. My question is, is that enought support on the track? Seems to me that when a heavy train ran over the track without the blocks, the track would sag, creating "soft spots."

What do you think?

[cwclark]

I use strip styrene and bass or balsa wood to superelevate the track...a good rule of thumb is to go no further than 8 degrees incline on the outside rail..i start off with styrene about .10 and elevate it to an apex of .40 then back to .10 in the length of the curve...Chuck[:D]

[Anonymous]

Chuck, how far apart do you place your wood or styrene? How are you measuring the degree of the rails?